From what I could determine the main concern when taking 550 is Red Mountain Pass. If you go to
www.irv2.com and search colorado 550 or red mountain pass you will get information from other RVers that have taken that route. The route seems passable for both RVs and big rigs depending on your experience and comfort level when mountain driving. I'm a flat-lander like you so anything over a 6% grade gets my attention.
Here's a Youtube video of a motorcycle going over the pass. You'll notice a tractor/trailer coming from the opposite direction so that's encouraging.
I read on irv2.com that 550 has quite a few pull offs where you can take in the gorgeous views and give your nerves, brakes and engine an opportunity to cool down and to get some color back in your knuckles...
Mesa Verde - We stayed at La Mesa Rv Park in Cortez. They aren't big but are big rig friendly and take Passport America from Sunday to Thursday. If you stay in Cortez and like Mexican food, I recommend La Fiesta by the Days Inn motel.... yum. You can buy their delicious salsa too. Good Stuff..
If your going to spend a lot of time in the mountains get the
Mountain Directory,www.<B style="FONT-SIZE: 14px; LINE-HEIGHT: 16px; FONT-FAMILY: arial, sans-serif; WHITE-SPACE: nowrap">mountaindirectory[/B].com/ . You can download it to your computer for easy reference.